/*
 * Copyright (C) 2007-2008 Esmertec AG.
 * Copyright (C) 2007-2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.mms.pdu;

import com.google.android.mms.ContentType;
import com.google.android.mms.InvalidHeaderValueException;
import com.google.android.mms.MmsException;
import com.google.android.mms.util.PduCache;
import com.google.android.mms.util.PduCacheEntry;
import com.google.android.mms.util.SqliteWrapper;

import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.DatabaseUtils;
import android.net.Uri;
import android.provider.Telephony.Mms;
import android.provider.Telephony.MmsSms;
import android.provider.Telephony.Threads;
import android.provider.Telephony.Mms.Addr;
import android.provider.Telephony.Mms.Part;
import android.provider.Telephony.MmsSms.PendingMessages;
import android.text.TextUtils;
import android.util.Config;
import android.util.Log;

import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

/**
 * This class is the high-level manager of PDU storage.
 */
public class PduPersister {
	private static final String TAG = "PduPersister";
	private static final boolean DEBUG = false;
	private static final boolean LOCAL_LOGV = DEBUG ? Config.LOGD : Config.LOGV;

	private static final long DUMMY_THREAD_ID = Long.MAX_VALUE;

	/**
	 * The uri of temporary drm objects.
	 */
	public static final String TEMPORARY_DRM_OBJECT_URI = "content://mms/" + Long.MAX_VALUE + "/part";
	/**
	 * Indicate that we transiently failed to process a MM.
	 */
	public static final int PROC_STATUS_TRANSIENT_FAILURE = 1;
	/**
	 * Indicate that we permanently failed to process a MM.
	 */
	public static final int PROC_STATUS_PERMANENTLY_FAILURE = 2;
	/**
	 * Indicate that we have successfully processed a MM.
	 */
	public static final int PROC_STATUS_COMPLETED = 3;

	private static PduPersister sPersister;
	private static final PduCache PDU_CACHE_INSTANCE;

	private static final int[] ADDRESS_FIELDS = new int[] { PduHeaders.BCC, PduHeaders.CC, PduHeaders.FROM,
			PduHeaders.TO };

	private static final String[] PDU_PROJECTION = new String[] { Mms._ID, Mms.MESSAGE_BOX, Mms.THREAD_ID,
			Mms.RETRIEVE_TEXT, Mms.SUBJECT, Mms.CONTENT_LOCATION, Mms.CONTENT_TYPE, Mms.MESSAGE_CLASS, Mms.MESSAGE_ID,
			Mms.RESPONSE_TEXT, Mms.TRANSACTION_ID, Mms.CONTENT_CLASS, Mms.DELIVERY_REPORT, Mms.MESSAGE_TYPE,
			Mms.MMS_VERSION, Mms.PRIORITY, Mms.READ_REPORT, Mms.READ_STATUS, Mms.REPORT_ALLOWED, Mms.RETRIEVE_STATUS,
			Mms.STATUS, Mms.DATE, Mms.DELIVERY_TIME, Mms.EXPIRY, Mms.MESSAGE_SIZE, Mms.SUBJECT_CHARSET,
			Mms.RETRIEVE_TEXT_CHARSET, };

	private static final int PDU_COLUMN_ID = 0;
	private static final int PDU_COLUMN_MESSAGE_BOX = 1;
	private static final int PDU_COLUMN_THREAD_ID = 2;
	private static final int PDU_COLUMN_RETRIEVE_TEXT = 3;
	private static final int PDU_COLUMN_SUBJECT = 4;
	private static final int PDU_COLUMN_CONTENT_LOCATION = 5;
	private static final int PDU_COLUMN_CONTENT_TYPE = 6;
	private static final int PDU_COLUMN_MESSAGE_CLASS = 7;
	private static final int PDU_COLUMN_MESSAGE_ID = 8;
	private static final int PDU_COLUMN_RESPONSE_TEXT = 9;
	private static final int PDU_COLUMN_TRANSACTION_ID = 10;
	private static final int PDU_COLUMN_CONTENT_CLASS = 11;
	private static final int PDU_COLUMN_DELIVERY_REPORT = 12;
	private static final int PDU_COLUMN_MESSAGE_TYPE = 13;
	private static final int PDU_COLUMN_MMS_VERSION = 14;
	private static final int PDU_COLUMN_PRIORITY = 15;
	private static final int PDU_COLUMN_READ_REPORT = 16;
	private static final int PDU_COLUMN_READ_STATUS = 17;
	private static final int PDU_COLUMN_REPORT_ALLOWED = 18;
	private static final int PDU_COLUMN_RETRIEVE_STATUS = 19;
	private static final int PDU_COLUMN_STATUS = 20;
	private static final int PDU_COLUMN_DATE = 21;
	private static final int PDU_COLUMN_DELIVERY_TIME = 22;
	private static final int PDU_COLUMN_EXPIRY = 23;
	private static final int PDU_COLUMN_MESSAGE_SIZE = 24;
	private static final int PDU_COLUMN_SUBJECT_CHARSET = 25;
	private static final int PDU_COLUMN_RETRIEVE_TEXT_CHARSET = 26;

	private static final String[] PART_PROJECTION = new String[] { Part._ID, Part.CHARSET, Part.CONTENT_DISPOSITION,
			Part.CONTENT_ID, Part.CONTENT_LOCATION, Part.CONTENT_TYPE, Part.FILENAME, Part.NAME, };

	private static final int PART_COLUMN_ID = 0;
	private static final int PART_COLUMN_CHARSET = 1;
	private static final int PART_COLUMN_CONTENT_DISPOSITION = 2;
	private static final int PART_COLUMN_CONTENT_ID = 3;
	private static final int PART_COLUMN_CONTENT_LOCATION = 4;
	private static final int PART_COLUMN_CONTENT_TYPE = 5;
	private static final int PART_COLUMN_FILENAME = 6;
	private static final int PART_COLUMN_NAME = 7;

	private static final HashMap<Uri, Integer> MESSAGE_BOX_MAP;
	// These map are used for convenience in persist() and load().
	private static final HashMap<Integer, Integer> CHARSET_COLUMN_INDEX_MAP;
	private static final HashMap<Integer, Integer> ENCODED_STRING_COLUMN_INDEX_MAP;
	private static final HashMap<Integer, Integer> TEXT_STRING_COLUMN_INDEX_MAP;
	private static final HashMap<Integer, Integer> OCTET_COLUMN_INDEX_MAP;
	private static final HashMap<Integer, Integer> LONG_COLUMN_INDEX_MAP;
	private static final HashMap<Integer, String> CHARSET_COLUMN_NAME_MAP;
	private static final HashMap<Integer, String> ENCODED_STRING_COLUMN_NAME_MAP;
	private static final HashMap<Integer, String> TEXT_STRING_COLUMN_NAME_MAP;
	private static final HashMap<Integer, String> OCTET_COLUMN_NAME_MAP;
	private static final HashMap<Integer, String> LONG_COLUMN_NAME_MAP;

	static {
		MESSAGE_BOX_MAP = new HashMap<Uri, Integer>();
		MESSAGE_BOX_MAP.put(Mms.Inbox.CONTENT_URI, Mms.MESSAGE_BOX_INBOX);
		MESSAGE_BOX_MAP.put(Mms.Sent.CONTENT_URI, Mms.MESSAGE_BOX_SENT);
		MESSAGE_BOX_MAP.put(Mms.Draft.CONTENT_URI, Mms.MESSAGE_BOX_DRAFTS);
		MESSAGE_BOX_MAP.put(Mms.Outbox.CONTENT_URI, Mms.MESSAGE_BOX_OUTBOX);

		CHARSET_COLUMN_INDEX_MAP = new HashMap<Integer, Integer>();
		CHARSET_COLUMN_INDEX_MAP.put(PduHeaders.SUBJECT, PDU_COLUMN_SUBJECT_CHARSET);
		CHARSET_COLUMN_INDEX_MAP.put(PduHeaders.RETRIEVE_TEXT, PDU_COLUMN_RETRIEVE_TEXT_CHARSET);

		CHARSET_COLUMN_NAME_MAP = new HashMap<Integer, String>();
		CHARSET_COLUMN_NAME_MAP.put(PduHeaders.SUBJECT, Mms.SUBJECT_CHARSET);
		CHARSET_COLUMN_NAME_MAP.put(PduHeaders.RETRIEVE_TEXT, Mms.RETRIEVE_TEXT_CHARSET);

		// Encoded string field code -> column index/name map.
		ENCODED_STRING_COLUMN_INDEX_MAP = new HashMap<Integer, Integer>();
		ENCODED_STRING_COLUMN_INDEX_MAP.put(PduHeaders.RETRIEVE_TEXT, PDU_COLUMN_RETRIEVE_TEXT);
		ENCODED_STRING_COLUMN_INDEX_MAP.put(PduHeaders.SUBJECT, PDU_COLUMN_SUBJECT);

		ENCODED_STRING_COLUMN_NAME_MAP = new HashMap<Integer, String>();
		ENCODED_STRING_COLUMN_NAME_MAP.put(PduHeaders.RETRIEVE_TEXT, Mms.RETRIEVE_TEXT);
		ENCODED_STRING_COLUMN_NAME_MAP.put(PduHeaders.SUBJECT, Mms.SUBJECT);

		// Text string field code -> column index/name map.
		TEXT_STRING_COLUMN_INDEX_MAP = new HashMap<Integer, Integer>();
		TEXT_STRING_COLUMN_INDEX_MAP.put(PduHeaders.CONTENT_LOCATION, PDU_COLUMN_CONTENT_LOCATION);
		TEXT_STRING_COLUMN_INDEX_MAP.put(PduHeaders.CONTENT_TYPE, PDU_COLUMN_CONTENT_TYPE);
		TEXT_STRING_COLUMN_INDEX_MAP.put(PduHeaders.MESSAGE_CLASS, PDU_COLUMN_MESSAGE_CLASS);
		TEXT_STRING_COLUMN_INDEX_MAP.put(PduHeaders.MESSAGE_ID, PDU_COLUMN_MESSAGE_ID);
		TEXT_STRING_COLUMN_INDEX_MAP.put(PduHeaders.RESPONSE_TEXT, PDU_COLUMN_RESPONSE_TEXT);
		TEXT_STRING_COLUMN_INDEX_MAP.put(PduHeaders.TRANSACTION_ID, PDU_COLUMN_TRANSACTION_ID);

		TEXT_STRING_COLUMN_NAME_MAP = new HashMap<Integer, String>();
		TEXT_STRING_COLUMN_NAME_MAP.put(PduHeaders.CONTENT_LOCATION, Mms.CONTENT_LOCATION);
		TEXT_STRING_COLUMN_NAME_MAP.put(PduHeaders.CONTENT_TYPE, Mms.CONTENT_TYPE);
		TEXT_STRING_COLUMN_NAME_MAP.put(PduHeaders.MESSAGE_CLASS, Mms.MESSAGE_CLASS);
		TEXT_STRING_COLUMN_NAME_MAP.put(PduHeaders.MESSAGE_ID, Mms.MESSAGE_ID);
		TEXT_STRING_COLUMN_NAME_MAP.put(PduHeaders.RESPONSE_TEXT, Mms.RESPONSE_TEXT);
		TEXT_STRING_COLUMN_NAME_MAP.put(PduHeaders.TRANSACTION_ID, Mms.TRANSACTION_ID);

		// Octet field code -> column index/name map.
		OCTET_COLUMN_INDEX_MAP = new HashMap<Integer, Integer>();
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.CONTENT_CLASS, PDU_COLUMN_CONTENT_CLASS);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.DELIVERY_REPORT, PDU_COLUMN_DELIVERY_REPORT);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.MESSAGE_TYPE, PDU_COLUMN_MESSAGE_TYPE);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.MMS_VERSION, PDU_COLUMN_MMS_VERSION);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.PRIORITY, PDU_COLUMN_PRIORITY);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.READ_REPORT, PDU_COLUMN_READ_REPORT);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.READ_STATUS, PDU_COLUMN_READ_STATUS);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.REPORT_ALLOWED, PDU_COLUMN_REPORT_ALLOWED);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.RETRIEVE_STATUS, PDU_COLUMN_RETRIEVE_STATUS);
		OCTET_COLUMN_INDEX_MAP.put(PduHeaders.STATUS, PDU_COLUMN_STATUS);

		OCTET_COLUMN_NAME_MAP = new HashMap<Integer, String>();
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.CONTENT_CLASS, Mms.CONTENT_CLASS);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.DELIVERY_REPORT, Mms.DELIVERY_REPORT);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.MESSAGE_TYPE, Mms.MESSAGE_TYPE);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.MMS_VERSION, Mms.MMS_VERSION);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.PRIORITY, Mms.PRIORITY);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.READ_REPORT, Mms.READ_REPORT);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.READ_STATUS, Mms.READ_STATUS);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.REPORT_ALLOWED, Mms.REPORT_ALLOWED);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.RETRIEVE_STATUS, Mms.RETRIEVE_STATUS);
		OCTET_COLUMN_NAME_MAP.put(PduHeaders.STATUS, Mms.STATUS);

		// Long field code -> column index/name map.
		LONG_COLUMN_INDEX_MAP = new HashMap<Integer, Integer>();
		LONG_COLUMN_INDEX_MAP.put(PduHeaders.DATE, PDU_COLUMN_DATE);
		LONG_COLUMN_INDEX_MAP.put(PduHeaders.DELIVERY_TIME, PDU_COLUMN_DELIVERY_TIME);
		LONG_COLUMN_INDEX_MAP.put(PduHeaders.EXPIRY, PDU_COLUMN_EXPIRY);
		LONG_COLUMN_INDEX_MAP.put(PduHeaders.MESSAGE_SIZE, PDU_COLUMN_MESSAGE_SIZE);

		LONG_COLUMN_NAME_MAP = new HashMap<Integer, String>();
		LONG_COLUMN_NAME_MAP.put(PduHeaders.DATE, Mms.DATE);
		LONG_COLUMN_NAME_MAP.put(PduHeaders.DELIVERY_TIME, Mms.DELIVERY_TIME);
		LONG_COLUMN_NAME_MAP.put(PduHeaders.EXPIRY, Mms.EXPIRY);
		LONG_COLUMN_NAME_MAP.put(PduHeaders.MESSAGE_SIZE, Mms.MESSAGE_SIZE);

		PDU_CACHE_INSTANCE = PduCache.getInstance();
	}

	private final Context mContext;
	private final ContentResolver mContentResolver;

	private PduPersister(Context context) {
		mContext = context;
		mContentResolver = context.getContentResolver();
	}

	/** Get(or create if not exist) an instance of PduPersister */
	public static PduPersister getPduPersister(Context context) {
		if ((sPersister == null) || !context.equals(sPersister.mContext)) {
			sPersister = new PduPersister(context);
		}

		return sPersister;
	}

	private void setEncodedStringValueToHeaders(Cursor c, int columnIndex, PduHeaders headers, int mapColumn) {
		String s = c.getString(columnIndex);
		if ((s != null) && (s.length() > 0)) {
			int charsetColumnIndex = CHARSET_COLUMN_INDEX_MAP.get(mapColumn);
			int charset = c.getInt(charsetColumnIndex);
			EncodedStringValue value = new EncodedStringValue(charset, getBytes(s));
			headers.setEncodedStringValue(value, mapColumn);
		}
	}

	private void setTextStringToHeaders(Cursor c, int columnIndex, PduHeaders headers, int mapColumn) {
		String s = c.getString(columnIndex);
		if (s != null) {
			headers.setTextString(getBytes(s), mapColumn);
		}
	}

	private void setOctetToHeaders(Cursor c, int columnIndex, PduHeaders headers, int mapColumn)
			throws InvalidHeaderValueException {
		if (!c.isNull(columnIndex)) {
			int b = c.getInt(columnIndex);
			headers.setOctet(b, mapColumn);
		}
	}

	private void setLongToHeaders(Cursor c, int columnIndex, PduHeaders headers, int mapColumn) {
		if (!c.isNull(columnIndex)) {
			long l = c.getLong(columnIndex);
			headers.setLongInteger(l, mapColumn);
		}
	}

	private Integer getIntegerFromPartColumn(Cursor c, int columnIndex) {
		if (!c.isNull(columnIndex)) {
			return c.getInt(columnIndex);
		}
		return null;
	}

	private byte[] getByteArrayFromPartColumn(Cursor c, int columnIndex) {
		if (!c.isNull(columnIndex)) {
			return getBytes(c.getString(columnIndex));
		}
		return null;
	}

	private PduPart[] loadParts(long msgId) throws MmsException {
		Cursor c = SqliteWrapper.query(mContext, mContentResolver, Uri.parse("content://mms/" + msgId + "/part"),
				PART_PROJECTION, null, null, null);

		PduPart[] parts = null;

		try {
			if ((c == null) || (c.getCount() == 0)) {
				if (LOCAL_LOGV) {
					Log.v(TAG, "loadParts(" + msgId + "): no part to load.");
				}
				return null;
			}

			int partCount = c.getCount();
			int partIdx = 0;
			parts = new PduPart[partCount];
			while (c.moveToNext()) {
				PduPart part = new PduPart();
				Integer charset = getIntegerFromPartColumn(c, PART_COLUMN_CHARSET);
				if (charset != null) {
					part.setCharset(charset);
				}

				byte[] contentDisposition = getByteArrayFromPartColumn(c, PART_COLUMN_CONTENT_DISPOSITION);
				if (contentDisposition != null) {
					part.setContentDisposition(contentDisposition);
				}

				byte[] contentId = getByteArrayFromPartColumn(c, PART_COLUMN_CONTENT_ID);
				if (contentId != null) {
					part.setContentId(contentId);
				}

				byte[] contentLocation = getByteArrayFromPartColumn(c, PART_COLUMN_CONTENT_LOCATION);
				if (contentLocation != null) {
					part.setContentLocation(contentLocation);
				}

				byte[] contentType = getByteArrayFromPartColumn(c, PART_COLUMN_CONTENT_TYPE);
				if (contentType != null) {
					part.setContentType(contentType);
				} else {
					throw new MmsException("Content-Type must be set.");
				}

				byte[] fileName = getByteArrayFromPartColumn(c, PART_COLUMN_FILENAME);
				if (fileName != null) {
					part.setFilename(fileName);
				}

				byte[] name = getByteArrayFromPartColumn(c, PART_COLUMN_NAME);
				if (name != null) {
					part.setName(name);
				}

				// Construct a Uri for this part.
				long partId = c.getLong(PART_COLUMN_ID);
				Uri partURI = Uri.parse("content://mms/part/" + partId);
				part.setDataUri(partURI);

				// For images/audio/video, we won't keep their data in Part
				// because their renderer accept Uri as source.
				String type = toIsoString(contentType);
				if (!ContentType.isImageType(type) && !ContentType.isAudioType(type) && !ContentType.isVideoType(type)) {
					ByteArrayOutputStream baos = new ByteArrayOutputStream();
					InputStream is = null;

					try {
						is = mContentResolver.openInputStream(partURI);

						byte[] buffer = new byte[256];
						int len = is.read(buffer);
						while (len >= 0) {
							baos.write(buffer, 0, len);
							len = is.read(buffer);
						}
					} catch (IOException e) {
						Log.e(TAG, "Failed to load part data", e);
						c.close();
						throw new MmsException(e);
					} finally {
						if (is != null) {
							try {
								is.close();
							} catch (IOException e) {
								Log.e(TAG, "Failed to close stream", e);
							} // Ignore
						}
					}
					part.setData(baos.toByteArray());
				}
				parts[partIdx++] = part;
			}
		} finally {
			if (c != null) {
				c.close();
			}
		}

		return parts;
	}

	private void loadAddress(long msgId, PduHeaders headers) {
		Cursor c = SqliteWrapper.query(mContext, mContentResolver, Uri.parse("content://mms/" + msgId + "/addr"),
				new String[] { Addr.ADDRESS, Addr.CHARSET, Addr.TYPE }, null, null, null);

		if (c != null) {
			try {
				while (c.moveToNext()) {
					String addr = c.getString(0);
					if (!TextUtils.isEmpty(addr)) {
						int addrType = c.getInt(2);
						switch (addrType) {
						case PduHeaders.FROM:
							headers.setEncodedStringValue(new EncodedStringValue(c.getInt(1), getBytes(addr)), addrType);
							break;
						case PduHeaders.TO:
						case PduHeaders.CC:
						case PduHeaders.BCC:
							headers.appendEncodedStringValue(new EncodedStringValue(c.getInt(1), getBytes(addr)),
									addrType);
							break;
						default:
							Log.e(TAG, "Unknown address type: " + addrType);
							break;
						}
					}
				}
			} finally {
				c.close();
			}
		}
	}

	/**
	 * Load a PDU from storage by given Uri.
	 * 
	 * @param uri
	 *            The Uri of the PDU to be loaded.
	 * @return A generic PDU object, it may be cast to dedicated PDU.
	 * @throws MmsException
	 *             Failed to load some fields of a PDU.
	 */
	public GenericPdu load(Uri uri) throws MmsException {
		PduCacheEntry cacheEntry = PDU_CACHE_INSTANCE.get(uri);
		if (cacheEntry != null) {
			return cacheEntry.getPdu();
		}

		Cursor c = SqliteWrapper.query(mContext, mContentResolver, uri, PDU_PROJECTION, null, null, null);
		PduHeaders headers = new PduHeaders();
		Set<Entry<Integer, Integer>> set;
		long msgId = ContentUris.parseId(uri);
		int msgBox;
		long threadId;

		try {
			if ((c == null) || (c.getCount() != 1) || !c.moveToFirst()) {
				throw new MmsException("Bad uri: " + uri);
			}

			msgBox = c.getInt(PDU_COLUMN_MESSAGE_BOX);
			threadId = c.getLong(PDU_COLUMN_THREAD_ID);

			set = ENCODED_STRING_COLUMN_INDEX_MAP.entrySet();
			for (Entry<Integer, Integer> e : set) {
				setEncodedStringValueToHeaders(c, e.getValue(), headers, e.getKey());
			}

			set = TEXT_STRING_COLUMN_INDEX_MAP.entrySet();
			for (Entry<Integer, Integer> e : set) {
				setTextStringToHeaders(c, e.getValue(), headers, e.getKey());
			}

			set = OCTET_COLUMN_INDEX_MAP.entrySet();
			for (Entry<Integer, Integer> e : set) {
				setOctetToHeaders(c, e.getValue(), headers, e.getKey());
			}

			set = LONG_COLUMN_INDEX_MAP.entrySet();
			for (Entry<Integer, Integer> e : set) {
				setLongToHeaders(c, e.getValue(), headers, e.getKey());
			}
		} finally {
			if (c != null) {
				c.close();
			}
		}

		// Check whether 'msgId' has been assigned a valid value.
		if (msgId == -1L) {
			throw new MmsException("Error! ID of the message: -1.");
		}

		// Load address information of the MM.
		loadAddress(msgId, headers);

		int msgType = headers.getOctet(PduHeaders.MESSAGE_TYPE);
		PduBody body = new PduBody();

		// For PDU which type is M_retrieve.conf or Send.req, we should
		// load multiparts and put them into the body of the PDU.
		if ((msgType == PduHeaders.MESSAGE_TYPE_RETRIEVE_CONF) || (msgType == PduHeaders.MESSAGE_TYPE_SEND_REQ)) {
			PduPart[] parts = loadParts(msgId);
			if (parts != null) {
				int partsNum = parts.length;
				for (int i = 0; i < partsNum; i++) {
					body.addPart(parts[i]);
				}
			}
		}

		GenericPdu pdu = null;
		switch (msgType) {
		case PduHeaders.MESSAGE_TYPE_NOTIFICATION_IND:
			pdu = new NotificationInd(headers);
			break;
		case PduHeaders.MESSAGE_TYPE_DELIVERY_IND:
			pdu = new DeliveryInd(headers);
			break;
		case PduHeaders.MESSAGE_TYPE_READ_ORIG_IND:
			pdu = new ReadOrigInd(headers);
			break;
		case PduHeaders.MESSAGE_TYPE_RETRIEVE_CONF:
			pdu = new RetrieveConf(headers, body);
			break;
		case PduHeaders.MESSAGE_TYPE_SEND_REQ:
			pdu = new SendReq(headers, body);
			break;
		case PduHeaders.MESSAGE_TYPE_ACKNOWLEDGE_IND:
			pdu = new AcknowledgeInd(headers);
			break;
		case PduHeaders.MESSAGE_TYPE_NOTIFYRESP_IND:
			pdu = new NotifyRespInd(headers);
			break;
		case PduHeaders.MESSAGE_TYPE_READ_REC_IND:
			pdu = new ReadRecInd(headers);
			break;
		case PduHeaders.MESSAGE_TYPE_SEND_CONF:
		case PduHeaders.MESSAGE_TYPE_FORWARD_REQ:
		case PduHeaders.MESSAGE_TYPE_FORWARD_CONF:
		case PduHeaders.MESSAGE_TYPE_MBOX_STORE_REQ:
		case PduHeaders.MESSAGE_TYPE_MBOX_STORE_CONF:
		case PduHeaders.MESSAGE_TYPE_MBOX_VIEW_REQ:
		case PduHeaders.MESSAGE_TYPE_MBOX_VIEW_CONF:
		case PduHeaders.MESSAGE_TYPE_MBOX_UPLOAD_REQ:
		case PduHeaders.MESSAGE_TYPE_MBOX_UPLOAD_CONF:
		case PduHeaders.MESSAGE_TYPE_MBOX_DELETE_REQ:
		case PduHeaders.MESSAGE_TYPE_MBOX_DELETE_CONF:
		case PduHeaders.MESSAGE_TYPE_MBOX_DESCR:
		case PduHeaders.MESSAGE_TYPE_DELETE_REQ:
		case PduHeaders.MESSAGE_TYPE_DELETE_CONF:
		case PduHeaders.MESSAGE_TYPE_CANCEL_REQ:
		case PduHeaders.MESSAGE_TYPE_CANCEL_CONF:
			throw new MmsException("Unsupported PDU type: " + Integer.toHexString(msgType));

		default:
			throw new MmsException("Unrecognized PDU type: " + Integer.toHexString(msgType));
		}

		cacheEntry = new PduCacheEntry(pdu, msgBox, threadId);
		PDU_CACHE_INSTANCE.put(uri, cacheEntry);
		return pdu;
	}

	private void persistAddress(long msgId, int type, EncodedStringValue[] array) {
		ContentValues values = new ContentValues(3);

		for (EncodedStringValue addr : array) {
			values.clear(); // Clear all values first.
			values.put(Addr.ADDRESS, toIsoString(addr.getTextString()));
			values.put(Addr.CHARSET, addr.getCharacterSet());
			values.put(Addr.TYPE, type);

			Uri uri = Uri.parse("content://mms/" + msgId + "/addr");
			SqliteWrapper.insert(mContext, mContentResolver, uri, values);
		}
	}

	public Uri persistPart(PduPart part, long msgId) throws MmsException {
		Uri uri = Uri.parse("content://mms/" + msgId + "/part");
		ContentValues values = new ContentValues(8);

		int charset = part.getCharset();
		if (charset != 0) {
			values.put(Part.CHARSET, charset);
		}

		String contentType = null;
		if (part.getContentType() != null) {
			contentType = toIsoString(part.getContentType());
			values.put(Part.CONTENT_TYPE, contentType);
			// To ensure the SMIL part is always the first part.
			if (ContentType.APP_SMIL.equals(contentType)) {
				values.put(Part.SEQ, -1);
			}
		} else {
			throw new MmsException("MIME type of the part must be set.");
		}

		if (part.getFilename() != null) {
			String fileName = new String(part.getFilename());
			values.put(Part.FILENAME, fileName);
		}

		if (part.getName() != null) {
			String name = new String(part.getName());
			values.put(Part.NAME, name);
		}

		Object value = null;
		if (part.getContentDisposition() != null) {
			value = toIsoString(part.getContentDisposition());
			values.put(Part.CONTENT_DISPOSITION, (String) value);
		}

		if (part.getContentId() != null) {
			value = toIsoString(part.getContentId());
			values.put(Part.CONTENT_ID, (String) value);
		}

		if (part.getContentLocation() != null) {
			value = toIsoString(part.getContentLocation());
			values.put(Part.CONTENT_LOCATION, (String) value);
		}

		Uri res = SqliteWrapper.insert(mContext, mContentResolver, uri, values);
		if (res == null) {
			throw new MmsException("Failed to persist part, return null.");
		}

		persistData(part, res, contentType);
		// After successfully store the data, we should update
		// the dataUri of the part.
		part.setDataUri(res);

		return res;
	}

	/**
	 * Save data of the part into storage. The source data may be given by a
	 * byte[] or a Uri. If it's a byte[], directly save it into storage,
	 * otherwise load source data from the dataUri and then save it. If the data
	 * is an image, we may scale down it according to user preference.
	 * 
	 * @param part
	 *            The PDU part which contains data to be saved.
	 * @param uri
	 *            The URI of the part.
	 * @param contentType
	 *            The MIME type of the part.
	 * @throws MmsException
	 *             Cannot find source data or error occurred while saving the
	 *             data.
	 */
	private void persistData(PduPart part, Uri uri, String contentType) throws MmsException {
		OutputStream os = null;
		InputStream is = null;

		try {
			os = mContentResolver.openOutputStream(uri);
			byte[] data = part.getData();
			if (data == null) {
				Uri dataUri = part.getDataUri();
				if ((dataUri == null) || (dataUri == uri)) {
					Log.w(TAG, "Can't find data for this part.");
					return;
				}
				is = mContentResolver.openInputStream(dataUri);

				if (LOCAL_LOGV) {
					Log.v(TAG, "Saving data to: " + uri);
				}

				byte[] buffer = new byte[256];
				for (int len = 0; (len = is.read(buffer)) != -1;) {
					os.write(buffer, 0, len);
				}
			} else {
				if (LOCAL_LOGV) {
					Log.v(TAG, "Saving data to: " + uri);
				}
				os.write(data);
			}
		} catch (FileNotFoundException e) {
			Log.e(TAG, "Failed to open Input/Output stream.", e);
			throw new MmsException(e);
		} catch (IOException e) {
			Log.e(TAG, "Failed to read/write data.", e);
			throw new MmsException(e);
		} finally {
			if (os != null) {
				try {
					os.close();
				} catch (IOException e) {
					Log.e(TAG, "IOException while closing: " + os, e);
				} // Ignore
			}
			if (is != null) {
				try {
					is.close();
				} catch (IOException e) {
					Log.e(TAG, "IOException while closing: " + is, e);
				} // Ignore
			}
		}
	}

	private void updateAddress(long msgId, int type, EncodedStringValue[] array) {
		// Delete old address information and then insert new ones.
		SqliteWrapper.delete(mContext, mContentResolver, Uri.parse("content://mms/" + msgId + "/addr"), Addr.TYPE + "="
				+ type, null);

		persistAddress(msgId, type, array);
	}

	/**
	 * Update headers of a SendReq.
	 * 
	 * @param uri
	 *            The PDU which need to be updated.
	 * @param pdu
	 *            New headers.
	 * @throws MmsException
	 *             Bad URI or updating failed.
	 */
	public void updateHeaders(Uri uri, SendReq sendReq) {
		PDU_CACHE_INSTANCE.purge(uri);

		ContentValues values = new ContentValues(9);
		byte[] contentType = sendReq.getContentType();
		if (contentType != null) {
			values.put(Mms.CONTENT_TYPE, toIsoString(contentType));
		}

		long date = sendReq.getDate();
		if (date != -1) {
			values.put(Mms.DATE, date);
		}

		int deliveryReport = sendReq.getDeliveryReport();
		if (deliveryReport != 0) {
			values.put(Mms.DELIVERY_REPORT, deliveryReport);
		}

		long expiry = sendReq.getExpiry();
		if (expiry != -1) {
			values.put(Mms.EXPIRY, expiry);
		}

		byte[] msgClass = sendReq.getMessageClass();
		if (msgClass != null) {
			values.put(Mms.MESSAGE_CLASS, toIsoString(msgClass));
		}

		int priority = sendReq.getPriority();
		if (priority != 0) {
			values.put(Mms.PRIORITY, priority);
		}

		int readReport = sendReq.getReadReport();
		if (readReport != 0) {
			values.put(Mms.READ_REPORT, readReport);
		}

		byte[] transId = sendReq.getTransactionId();
		if (transId != null) {
			values.put(Mms.TRANSACTION_ID, toIsoString(transId));
		}

		EncodedStringValue subject = sendReq.getSubject();
		if (subject != null) {
			values.put(Mms.SUBJECT, toIsoString(subject.getTextString()));
			values.put(Mms.SUBJECT_CHARSET, subject.getCharacterSet());
		}

		PduHeaders headers = sendReq.getPduHeaders();
		HashSet<String> recipients = new HashSet<String>();
		for (int addrType : ADDRESS_FIELDS) {
			EncodedStringValue[] array = null;
			if (addrType == PduHeaders.FROM) {
				EncodedStringValue v = headers.getEncodedStringValue(addrType);
				if (v != null) {
					array = new EncodedStringValue[1];
					array[0] = v;
				}
			} else {
				array = headers.getEncodedStringValues(addrType);
			}

			if (array != null) {
				long msgId = ContentUris.parseId(uri);
				updateAddress(msgId, addrType, array);
				if (addrType == PduHeaders.TO) {
					for (EncodedStringValue v : array) {
						if (v != null) {
							recipients.add(v.getString());
						}
					}
				}
			}
		}

		long threadId = Threads.getOrCreateThreadId(mContext, recipients);
		values.put(Mms.THREAD_ID, threadId);

		SqliteWrapper.update(mContext, mContentResolver, uri, values, null, null);
	}

	private void updatePart(Uri uri, PduPart part) throws MmsException {
		ContentValues values = new ContentValues(7);

		int charset = part.getCharset();
		if (charset != 0) {
			values.put(Part.CHARSET, charset);
		}

		String contentType = null;
		if (part.getContentType() != null) {
			contentType = toIsoString(part.getContentType());
			values.put(Part.CONTENT_TYPE, contentType);
		} else {
			throw new MmsException("MIME type of the part must be set.");
		}

		if (part.getFilename() != null) {
			String fileName = new String(part.getFilename());
			values.put(Part.FILENAME, fileName);
		}

		if (part.getName() != null) {
			String name = new String(part.getName());
			values.put(Part.NAME, name);
		}

		Object value = null;
		if (part.getContentDisposition() != null) {
			value = toIsoString(part.getContentDisposition());
			values.put(Part.CONTENT_DISPOSITION, (String) value);
		}

		if (part.getContentId() != null) {
			value = toIsoString(part.getContentId());
			values.put(Part.CONTENT_ID, (String) value);
		}

		if (part.getContentLocation() != null) {
			value = toIsoString(part.getContentLocation());
			values.put(Part.CONTENT_LOCATION, (String) value);
		}

		SqliteWrapper.update(mContext, mContentResolver, uri, values, null, null);

		// Only update the data when:
		// 1. New binary data supplied or
		// 2. The Uri of the part is different from the current one.
		if ((part.getData() != null) || (uri != part.getDataUri())) {
			persistData(part, uri, contentType);
		}
	}

	/**
	 * Update all parts of a PDU.
	 * 
	 * @param uri
	 *            The PDU which need to be updated.
	 * @param body
	 *            New message body of the PDU.
	 * @throws MmsException
	 *             Bad URI or updating failed.
	 */
	public void updateParts(Uri uri, PduBody body) throws MmsException {
		PduCacheEntry cacheEntry = PDU_CACHE_INSTANCE.get(uri);
		if (cacheEntry != null) {
			((MultimediaMessagePdu) cacheEntry.getPdu()).setBody(body);
		}

		ArrayList<PduPart> toBeCreated = new ArrayList<PduPart>();
		HashMap<Uri, PduPart> toBeUpdated = new HashMap<Uri, PduPart>();

		int partsNum = body.getPartsNum();
		StringBuilder filter = new StringBuilder().append('(');
		for (int i = 0; i < partsNum; i++) {
			PduPart part = body.getPart(i);
			Uri partUri = part.getDataUri();
			if ((partUri == null) || !partUri.getAuthority().startsWith("mms")) {
				toBeCreated.add(part);
			} else {
				toBeUpdated.put(partUri, part);

				// Don't use 'i > 0' to determine whether we should append
				// 'AND' since 'i = 0' may be skipped in another branch.
				if (filter.length() > 1) {
					filter.append(" AND ");
				}

				filter.append(Part._ID);
				filter.append("!=");
				DatabaseUtils.appendEscapedSQLString(filter, partUri.getLastPathSegment());
			}
		}
		filter.append(')');

		long msgId = ContentUris.parseId(uri);

		// Remove the parts which doesn't exist anymore.
		SqliteWrapper.delete(mContext, mContentResolver, Uri.parse(Mms.CONTENT_URI + "/" + msgId + "/part"),
				filter.length() > 2 ? filter.toString() : null, null);

		// Create new parts which didn't exist before.
		for (PduPart part : toBeCreated) {
			persistPart(part, msgId);
		}

		// Update the modified parts.
		for (Map.Entry<Uri, PduPart> e : toBeUpdated.entrySet()) {
			updatePart(e.getKey(), e.getValue());
		}
	}

	/**
	 * Persist a PDU object to specific location in the storage.
	 * 
	 * @param pdu
	 *            The PDU object to be stored.
	 * @param uri
	 *            Where to store the given PDU object.
	 * @return A Uri which can be used to access the stored PDU.
	 */
	public Uri persist(GenericPdu pdu, Uri uri) throws MmsException {
		if (uri == null) {
			throw new MmsException("Uri may not be null.");
		}

		Integer msgBox = MESSAGE_BOX_MAP.get(uri);
		if (msgBox == null) {
			throw new MmsException("Bad destination, must be one of " + "content://mms/inbox, content://mms/sent, "
					+ "content://mms/drafts, content://mms/outbox, " + "content://mms/temp.");
		}

		PduHeaders header = pdu.getPduHeaders();
		PduBody body = null;
		ContentValues values = new ContentValues();
		Set<Entry<Integer, String>> set;

		set = ENCODED_STRING_COLUMN_NAME_MAP.entrySet();
		for (Entry<Integer, String> e : set) {
			int field = e.getKey();
			EncodedStringValue encodedString = header.getEncodedStringValue(field);
			if (encodedString != null) {
				String charsetColumn = CHARSET_COLUMN_NAME_MAP.get(field);
				values.put(e.getValue(), toIsoString(encodedString.getTextString()));
				values.put(charsetColumn, encodedString.getCharacterSet());
			}
		}

		set = TEXT_STRING_COLUMN_NAME_MAP.entrySet();
		for (Entry<Integer, String> e : set) {
			byte[] text = header.getTextString(e.getKey());
			if (text != null) {
				values.put(e.getValue(), toIsoString(text));
			}
		}

		set = OCTET_COLUMN_NAME_MAP.entrySet();
		for (Entry<Integer, String> e : set) {
			int b = header.getOctet(e.getKey());
			if (b != 0) {
				values.put(e.getValue(), b);
			}
		}

		set = LONG_COLUMN_NAME_MAP.entrySet();
		for (Entry<Integer, String> e : set) {
			long l = header.getLongInteger(e.getKey());
			if (l != -1L) {
				values.put(e.getValue(), l);
			}
		}

		HashMap<Integer, EncodedStringValue[]> addressMap = new HashMap<Integer, EncodedStringValue[]>(
				ADDRESS_FIELDS.length);
		// Save address information.
		for (int addrType : ADDRESS_FIELDS) {
			EncodedStringValue[] array = null;
			if (addrType == PduHeaders.FROM) {
				EncodedStringValue v = header.getEncodedStringValue(addrType);
				if (v != null) {
					array = new EncodedStringValue[1];
					array[0] = v;
				}
			} else {
				array = header.getEncodedStringValues(addrType);
			}
			addressMap.put(addrType, array);
		}

		HashSet<String> recipients = new HashSet<String>();
		long threadId = DUMMY_THREAD_ID;
		int msgType = pdu.getMessageType();
		// Here we only allocate thread ID for M-Notification.ind,
		// M-Retrieve.conf and M-Send.req.
		// Some of other PDU types may be allocated a thread ID outside
		// this scope.
		if ((msgType == PduHeaders.MESSAGE_TYPE_NOTIFICATION_IND) || (msgType == PduHeaders.MESSAGE_TYPE_RETRIEVE_CONF)
				|| (msgType == PduHeaders.MESSAGE_TYPE_SEND_REQ)) {
			EncodedStringValue[] array = null;
			switch (msgType) {
			case PduHeaders.MESSAGE_TYPE_NOTIFICATION_IND:
			case PduHeaders.MESSAGE_TYPE_RETRIEVE_CONF:
				array = addressMap.get(PduHeaders.FROM);
				break;
			case PduHeaders.MESSAGE_TYPE_SEND_REQ:
				array = addressMap.get(PduHeaders.TO);
				break;
			}

			if (array != null) {
				for (EncodedStringValue v : array) {
					if (v != null) {
						recipients.add(v.getString());
					}
				}
			}
			threadId = Threads.getOrCreateThreadId(mContext, recipients);
		}
		values.put(Mms.THREAD_ID, threadId);

		// Save parts first to avoid inconsistent message is loaded
		// while saving the parts.
		long dummyId = System.currentTimeMillis(); // Dummy ID of the msg.
		// Get body if the PDU is a RetrieveConf or SendReq.
		if (pdu instanceof MultimediaMessagePdu) {
			body = ((MultimediaMessagePdu) pdu).getBody();
			// Start saving parts if necessary.
			if (body != null) {
				int partsNum = body.getPartsNum();
				for (int i = 0; i < partsNum; i++) {
					PduPart part = body.getPart(i);
					persistPart(part, dummyId);
				}
			}
		}

		Uri res = SqliteWrapper.insert(mContext, mContentResolver, uri, values);
		if (res == null) {
			throw new MmsException("persist() failed: return null.");
		}

		// Get the real ID of the PDU and update all parts which were
		// saved with the dummy ID.
		long msgId = ContentUris.parseId(res);
		values = new ContentValues(1);
		values.put(Part.MSG_ID, msgId);
		SqliteWrapper.update(mContext, mContentResolver, Uri.parse("content://mms/" + dummyId + "/part"), values, null,
				null);
		// We should return the longest URI of the persisted PDU, for
		// example, if input URI is "content://mms/inbox" and the _ID of
		// persisted PDU is '8', we should return "content://mms/inbox/8"
		// instead of "content://mms/8".
		// FIXME: Should the MmsProvider be responsible for this???
		res = Uri.parse(uri + "/" + msgId);

		// Save address information.
		for (int addrType : ADDRESS_FIELDS) {
			EncodedStringValue[] array = addressMap.get(addrType);
			if (array != null) {
				persistAddress(msgId, addrType, array);
			}
		}

		return res;
	}

	/**
	 * Move a PDU object from one location to another.
	 * 
	 * @param from
	 *            Specify the PDU object to be moved.
	 * @param to
	 *            The destination location, should be one of the following:
	 *            "content://mms/inbox", "content://mms/sent",
	 *            "content://mms/drafts", "content://mms/outbox",
	 *            "content://mms/trash".
	 * @return New Uri of the moved PDU.
	 * @throws MmsException
	 *             Error occurred while moving the message.
	 */
	public Uri move(Uri from, Uri to) throws MmsException {
		// Check whether the 'msgId' has been assigned a valid value.
		long msgId = ContentUris.parseId(from);
		if (msgId == -1L) {
			throw new MmsException("Error! ID of the message: -1.");
		}

		// Get corresponding int value of destination box.
		Integer msgBox = MESSAGE_BOX_MAP.get(to);
		if (msgBox == null) {
			throw new MmsException("Bad destination, must be one of " + "content://mms/inbox, content://mms/sent, "
					+ "content://mms/drafts, content://mms/outbox, " + "content://mms/temp.");
		}

		ContentValues values = new ContentValues(1);
		values.put(Mms.MESSAGE_BOX, msgBox);
		SqliteWrapper.update(mContext, mContentResolver, from, values, null, null);
		return ContentUris.withAppendedId(to, msgId);
	}

	/**
	 * Wrap a byte[] into a String.
	 */
	public static String toIsoString(byte[] bytes) {
		try {
			return new String(bytes, CharacterSets.MIMENAME_ISO_8859_1);
		} catch (UnsupportedEncodingException e) {
			// Impossible to reach here!
			Log.e(TAG, "ISO_8859_1 must be supported!", e);
			return "";
		}
	}

	/**
	 * Unpack a given String into a byte[].
	 */
	public static byte[] getBytes(String data) {
		try {
			return data.getBytes(CharacterSets.MIMENAME_ISO_8859_1);
		} catch (UnsupportedEncodingException e) {
			// Impossible to reach here!
			Log.e(TAG, "ISO_8859_1 must be supported!", e);
			return new byte[0];
		}
	}

	/**
	 * Remove all objects in the temporary path.
	 */
	public void release() {
		Uri uri = Uri.parse(TEMPORARY_DRM_OBJECT_URI);
		SqliteWrapper.delete(mContext, mContentResolver, uri, null, null);
	}

	/**
	 * Find all messages to be sent or downloaded before certain time.
	 */
	public Cursor getPendingMessages(long dueTime) {
		Uri.Builder uriBuilder = PendingMessages.CONTENT_URI.buildUpon();
		uriBuilder.appendQueryParameter("protocol", "mms");

		String selection = PendingMessages.ERROR_TYPE + " < ?" + " AND " + PendingMessages.DUE_TIME + " <= ?";

		String[] selectionArgs = new String[] { String.valueOf(MmsSms.ERR_TYPE_GENERIC_PERMANENT),
				String.valueOf(dueTime) };

		return SqliteWrapper.query(mContext, mContentResolver, uriBuilder.build(), null, selection, selectionArgs,
				PendingMessages.DUE_TIME);
	}
}
